Percutaneous Compression Plate (PCCP) Versus Dynamic Hip Screw (DHS) For Intertrochanteric Fractures: A Meta-analysis

BackgroundThe intertrochanter fracture, which usually happens among the old, accounts for fifty pencent of hip fractures.Expectant treatment always cause many complications and a high mortality. Surgical treatments are recommended currently. Conventional internal fixators in China are Dynamic hip screw(DHS), GAMMA nail, PFNA, et al. Since invented in 1955, DHS was widespread used. With the isometric and dynamic compression effect, it works well for the fixation for fermoral head and neck. But it is weak in rotation control, usually one or two pieces of lag screw are required. In addition, two defects:serious injury, and long duration of surgery makes it not suitable for those who are of low tolerance or slow healing atfer surgery. In the 1990s, Gotfried developed a new micro invasive internal fixation system for intertrochanteric fracture-percutaneous compression plate, PCCP. Supporters for this system believe the operation has several advantages:slighter trauma, less blood loss, shorter operation time, lower infection rate and mild pain, etc. However, some scholars declare that PCCP has no distinct advantages over DHS on clinical trials. Academic disptues on the advantages of PCCP and DHS are still going on. Agreement on the material for internal fixation has not been achieved. ObjectiveTo systematically evaluate the efficacy of percutaneous compression plate(PCCP) comparing dynamic hip screw(DHS) by aspects below,1. operating time2. post-operative infection3. post-operative mortality(wihtin 1 year)4. length of stay in hospitalMethod1. According to the different purpose, detailed inclusion and exclusion criteria were established by PICO (Participant, Intervention, Comparator, Outcome) steps, and then comprehensive search strategy of literature were made to search the relevant randomized controlled trials(RCTs) and controlled clinical trials, CCTs.2. According to Medline, Embase, and Chinese Biomedical Database were retrieved for RCTs and CCTs that comparing PCCP and DHS for the treatment of intertrochanteric fractures before the end of December 2010. Furthermore, we also handsearched relevant reference and some Chinese orthopedic journals. Finally, RCTs which met the specific inclusion and exclusion criteria were included.3. The methodology quality of each inclusion study was critically assessed according to the quality criteria of RCT which include four items:randomization, allocation concealment, follow-up and blindness. The validity of each trail was refered to as A, B or C scale according to Cochrane handbook for systematic reviews.4. After critical appraisal, data of each RCT on relevant outcome parameter were extracted. Software RevMan 5.0, the Cochrane Collaboration provided were used for meta-analysis. For each study, relative risk(RR) and 95% confidence intervals(95%CI) were calculated for dichotomous outcomes and weighted mean differences(WMD) and 95% confidence intervals(95%CI) were calculated for continuous outcomes. If interventions of each trial were different, subgroup analysis should be applied. Heterogeneity between comparable studies was tested with the use of a standard chi-square test. The significant levela= 0.1, and heterogeneity is analyzed by I2. WhenI2<25% means no heterogeneity, when 25%<I2<50% means that heterogeneity is medium. When I2>50% means that heterogeneity is significant, and the random-effects model should be used. However, if the results of certain outcome measures were not pooled or if the outcome events rarely happened, evaluation should rely on detailed description. Sensibility analysis means that when t after analyzed separately by fixed-effect model and random-effects model, he results are steady if they are the same.ResultThree RCTs and one CCT was included,557 cases(246 PCCP cases and 311 DHS cases)were involved. All of the four studies described the randomization. One study described the concealment.None of they described the blindness. Follow-up failure happened in one study. Therefore, all of the studies belong the B scale in study quality, and may be with medium bias.The result of Meta analysis demonstrated that,1. Operating timeAll of the four studies were included, refering to 232 PCCP cases and 293 DHS cases.Data analysis showed that there is no statistic differences in operating time between PCCP and DHS(WMD=-10.96,95% CI-26.47～4.56, P=0.17).2. Post-operative infectionThree studies,including two RTCs and one CCTs, described the post-operative infection by comparing PCCP(193 cases) and DHS(249 cases).The result showed that there is no statistic differences in post-operative infection between PCCP and DHS(RR=0.43,95% CI 0.55～1.28,P=0.13).3. post-operative mortality(wihtin 1 year) All of the four studies were included, refering to 246 PCCP cases and 311 DHS cases.Data analysis showed that there is no statistic differences in post-operative mortality between PCCP and DHS(RR=0.88,95% CI 0.55～1.40, P=0.58).4. length of stay in hospitalThree studies described the length of stay in hospital by comparing PCCP(193 cases) and DHS(249 cases).The result showed that there is no statistic differences in the length of stay between PCCP and DUS(WMD=-0.77,95% CI-2.09～1.94, P= 0.94).ConclusionAs the aging problem’s getting more and more serious, the intertrochanteric fracture, which familiar and usually acompany with serious complication, high mortality, and difficult cure, is more and more emphasized. After the 90s of 20th century, as the conception of micro invasive was promoted and then clinically pratized, some traditional fixation were replaced by those of new micro-invasive. PCCP, invented according to the idea of "curing the intertrochanteric fracture by the way of micro invasive", was now used today. It may be replace DHS, the traditional fixation for the intertrochanteric fracture. PCCP is constituded with one plate, two femoral-neck screws and three femoral screws. After the reduction of the fracture under X-ray, PCCP will be assembled in the interior through a percutaneous incision with "non-touch" technology. Supporters believe that PCCP has the advantages of reliable, micro invasive and safe; fracture ends are needn’t exposed, which lead to a slighter trauma and a less blood loss; double-axis fixation could control the rotaional displacement; The telescopic femoral neck screws could control the compression of fracture ends, which provide a micro motional environment and is beneficial to the fracture healing; The lock mechanism provides a totally stability. Brandt,et al. declare that PCCP’s control of rotation and axis displacement is better than that of DHS’s after a biomechanical test. Some scholars said that PCCP is good for the fracture healing of osteoporosis patients, and its cut-out rate is lower. However, some scholars believe that PCCP has its advantage only in the theoretical field. Our study was comparing operating time, post-operation infection, post-operation mortality and the length of stay in hospital of both fixation by evidence-based medicine means, in the hope of finding the evidence for clinical decision.1. Comparing PCCP to DHS in operating time, our Meta analysis showed that there is no statistic differences.In another words, we can not approved that PCCP and DHS are different in operating time. But we can see the trend of that operating time of PCCP is shorter. As being more and more widely used, the operating time of PCCP may be shorter.2. Data analysis demonstrated that there is no statistic differences in post-operation infection. We need more high-quality and large-samples RCTs to aprove the conclusion.3. Current evidence shows that mortalities in one year are the same between PCCP and DHS. Because the intertrochanter fracture usually happen among the old, mortality is high.Also, mortality can be influenced by many effects. To establish the difference of their mortality,high-quality RCTs are needed.4. We failed to approved that there is significant difference in the length of stay in hospital. More date and further analysis are needed.5. Overall,although there are no statistic differences in operating time, post-operative infection, post-operative mortality(wihtin 1 year) and the length of stay in hospital,we can still find a better trend of PCCP.6. Limitation lies in our study. First, studies included are not more enough,and belong to B scale.Only public pulished references are considered, which may diminish the effect of analysis. Bias from publishment, area or including standard is a potential and serious problem.all above may limite the accuracy of our study. Second, PCCP is a new tenique especially in China. Few references can be included, which limites the evaluation. It is rather necessary to have a further and comprehensive systematic review when PCCP is widely used and its tenique is quite mature.